// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/resolve_proxy_msg_helper.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/compiler_specific.h"
#include "content/common/view_messages.h"
#include "net/base/net_errors.h"
#include "net/log/net_log_with_source.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_context_getter.h"

namespace content {

ResolveProxyMsgHelper::ResolveProxyMsgHelper(
    net::URLRequestContextGetter* getter)
    : BrowserMessageFilter(ViewMsgStart)
    , context_getter_(getter)
    , proxy_service_(NULL)
{
}

ResolveProxyMsgHelper::ResolveProxyMsgHelper(net::ProxyService* proxy_service)
    : BrowserMessageFilter(ViewMsgStart)
    , proxy_service_(proxy_service)
{
}

bool ResolveProxyMsgHelper::OnMessageReceived(const IPC::Message& message)
{
    bool handled = true;
    IPC_BEGIN_MESSAGE_MAP(ResolveProxyMsgHelper, message)
    IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_ResolveProxy, OnResolveProxy)
    IPC_MESSAGE_UNHANDLED(handled = false)
    IPC_END_MESSAGE_MAP()
    return handled;
}

void ResolveProxyMsgHelper::OnResolveProxy(const GURL& url,
    IPC::Message* reply_msg)
{
    // Enqueue the pending request.
    pending_requests_.push_back(PendingRequest(url, reply_msg));

    // If nothing is in progress, start.
    if (pending_requests_.size() == 1)
        StartPendingRequest();
}

ResolveProxyMsgHelper::~ResolveProxyMsgHelper()
{
    // Clear all pending requests if the ProxyService is still alive (if we have a
    // default request context or override).
    if (!pending_requests_.empty()) {
        PendingRequest req = pending_requests_.front();
        proxy_service_->CancelPacRequest(req.pac_req);
    }

    for (PendingRequestList::iterator it = pending_requests_.begin();
         it != pending_requests_.end();
         ++it) {
        delete it->reply_msg;
    }

    pending_requests_.clear();
}

void ResolveProxyMsgHelper::OnResolveProxyCompleted(int result)
{
    CHECK(!pending_requests_.empty());

    const PendingRequest& completed_req = pending_requests_.front();
    ViewHostMsg_ResolveProxy::WriteReplyParams(
        completed_req.reply_msg, result == net::OK, proxy_info_.ToPacString());
    Send(completed_req.reply_msg);

    // Clear the current (completed) request.
    pending_requests_.pop_front();

    // Start the next request.
    if (!pending_requests_.empty())
        StartPendingRequest();
}

void ResolveProxyMsgHelper::StartPendingRequest()
{
    PendingRequest& req = pending_requests_.front();

    // Verify the request wasn't started yet.
    DCHECK(NULL == req.pac_req);

    if (context_getter_.get()) {
        proxy_service_ = context_getter_->GetURLRequestContext()->proxy_service();
        context_getter_ = NULL;
    }

    // Start the request.
    int result = proxy_service_->ResolveProxy(
        req.url, std::string(), &proxy_info_,
        base::Bind(&ResolveProxyMsgHelper::OnResolveProxyCompleted,
            base::Unretained(this)),
        &req.pac_req, NULL, net::NetLogWithSource());

    // Completed synchronously.
    if (result != net::ERR_IO_PENDING)
        OnResolveProxyCompleted(result);
}

} // namespace content
